1996 Pump Questions

[gravitydrno]

Went out of the 4th of July weekend and she was the same as always but I have now decided to get into the propulsion issues...Port side seemed to be the worst so I started there.
Port pump removal went OK but could tell all O-rings were dried out and drive shaft was very rusted and pitted and even the splines looked like they had excessive wear (don’t know how…). Carbon seal looked good and so did wear ring and impeller….even appeared to have good clearance. Through hull fitting looked good.
Three pump veins have small cracks (about ¼”) where they join the outer housing on the inlet side and one other is cracked all along the same area from inlet side to nozzle side and a hole large enough to fit a bb through. Assume this a wasted item? Or can they be fixed? Also, upon inspection the pump mount, ride plate and intake grate all look good, any reason to remove these and re-seal since I have already gone this far?

Tried to post pics but would not upload for some reason....

 

[gravitydrno]

Anyone have an opinion?

 

[Waterluvr]

Anyone have an opinion?

Your initial post didn't mention anything about the nature of the trouble you were having that caused you to get into the pump housing in the first place other than you were having propulsion issues, that's why no one's answering you.

You said impeller and wear ring clearances looked good but didn't list any measurements (I don't know anyone that can eye ball .040 of wear and make that call of being in or out of spec without sliding a feeler gauge in to get some accurate measurements).

Sounds like you have an excess of corrosion on your stainless pump components, is the boat used in salt water or moored in the water near docks with shore power locations that might be dumping off some voltage into the water causing galvanic corrosion?

 

[gravitydrno]

Sorry, to be more clear motors run...ok at best. Hard to be more accurate than that because tachs are not working correctly must go by sound. At times the boat takes more than a minute to plane out others it will plane a bit sooner. So from a stop it has little to no propulsion. I never measured the clearances with gauges (bought some today) but I did slide a piece of paper in and then doubled and it had pressure, not the best but enough to show real close to tolerance (not saying I can eye ball .040, which is why I bought gauges before re-using impeller) I have purchased all new from PTO out except will reuse impeller if it show good clearances.

My question was on the condition of the removed housing. Will the 1/4" long cracks on the input side of the three veins and the small hole make the pump unrepairable?

Should the ride pllate and intake grate be removed since I have gone this far already or just ensure they Re sealed?

 

[Waterluvr]

Cracks, holes etc. anything that changes the configuration of the pump veins or creates a pitted surface is going to impede the flow of water volume past it affecting the pump's ability to turn shaft horsepower into thrust. Some pictures would help but it sounds like it's hurt enough to be causing you some minor loss in efficiency but none of that matters if your motors are not running properly.

As far as the ride plate and intake grate are concerned it sounds like you need to worry about getting your motors running and in tune and fix the tachs before you start worrying about anything else. You can bolt all new pumps on the boat if you're not making horsepower and getting into the top of the rpm range none of that matters it won't ever get out of it's own way.

 

[gravitydrno]

Motors are running ok but without accurate tachs I cannot say exactly what rpm they are running. Once the boat is on plane everything seems fine BUT my issue has been getting it there. This is a restore project so I am fixing things as I go, got motors running well enough to find out there was major cavitation issues with the port side so I began there knowing that I will be rebuilding two motors in the future. They have good compression (140 port/138 starboard) but oil leaks into motors when they sit for a week or moe. When I am getting that back together I will be inspecting the starboard side and making needed corrections there. There were many issues with this boat and I just had to pick a route that I could best determine whether I was willing to put out the amount of money it was going to take. Pumps were my final assessment, I love the boat and have decided I will complete the restoration.


Waterlvr, I appreciate the information!

 

[Waterluvr]

If you have oil leaking into the motors from the oil tank while it is sitting on the trailer your crank shaft seals are gone. Stop running the motors, there is nothing you can do to avoid them running lean and destroying themselves at this point from the crank seal leaks.

Pull them out and have them rebuilt while it's still an option, if you further destroy them you will lose the core value if you send a rod through the case.

 

[gravitydrno]

Good information. I was told by a mechanic that there was no issue running them knowing I was going to be rebuilding in the near future.

Thanks for the info on the core for rebuild because I was going to put two SBT rebuilds in after this season.

 

[grinditout]

Pull them and pressure test.

 

[Waterluvr]

Good information. I was told by a mechanic that there was no issue running them knowing I was going to be rebuilding in the near future.

Thanks for the info on the core for rebuild because I was going to put two SBT rebuilds in after this season.

That would be tragic if you have the original motors still in the boat, do some homework and educate yourself why the most reputable machine shops that rebuild Rotax 2 strokes won't even take a previously remanufactured engine from some *other* companies as a core.

If they are original motors, do yourself a favor and keep them if you plan to own this boat for the long haul 2 stroke Rotax engines are no longer being produced and it's really in your best interest to retain your original power and have it properly rebuilt at a machine shop and reinstall them.

 

[grinditout]

Most folks will not pay what it takes, to do the job right.
I charge 500 and rebuild the carbs labor only. That is delivered to me.

 

[grinditout]

You need this> http://www.ebay.com/itm/161286962983?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Keep your eye out.

 

[Sportster-2001-951C-Stock]

Yes, if your outer crankshaft seals are leaking then you will experience problems trying to get consistent air/fuel ratios and run the risk of lean-seizure, at the least if the inner seals are leaking oil and flooding the crankcase with oil while sitting static then your outer seals may be leaking air as well and at this point a crankcase pressure differential test should be performed.

Personally, I think there are pitfalls to avoid when having a motor rebuilt, I'm not sold on the idea of clugeing them back together by welding the press-fit crank or other questionable practices but realize sometimes price becomes an issue.

When it comes time, I don't plan on having my engine remaned by the cheapest route. Short of doing this myself depending on replacement parts availability I will probably ask SES or Full Bore to do the job with preference toward the former.

 

[Waterluvr]

Yes, if your outer crankshaft seals are leaking then you will experience problems trying to get consistent air/fuel ratios and run the risk of lean-seizure, at the least if the inner seals are leaking oil and flooding the crankcase with oil while sitting static then your outer seals may be leaking air as well and at this point a crankcase pressure differential test should be performed.

Personally, I think there are pitfalls to avoid when having a motor rebuilt, I'm not sold on the idea of clugeing them back together by welding the press-fit crank or other questionable practices but realize sometimes price becomes an issue.

When it comes time, I don't plan on having my engine remaned by the cheapest route. Short of doing this myself depending on replacement parts availability I will probably ask SES or Full Bore to do the job with preference toward the former.

Ditto on either of those builders, mine will go to Full Bore for their platinum service when it's time as they are close and do it right. This shoddy business of welding cranks and head volume expansions for grossly oversized bores to get large numbers of motors back out the door on the cheap isn't for me, and I sure wouldn't have put one in a customer's boat with my name on the job.

 

[grinditout]

Dan uses wsm cranks.
He would not take a full engune right now to busy for months.
I use hotrods cranks.

 

[grinditout]

Really welded cranks and sbt engines have there place.
It depends on the person

I bought 2k in tools and would not suggest you do that for 1 engine.
I can also say I go a step further than fullbore when I cc the head and squish ring.
They put a number 5 base gasket and let it ride.

 

[gravitydrno]

Thanks guys I am hearing you and understand what you are saying, makes sense. I like that SES is within easy driving distance from me (by my normal driving habits anyway!) I have decided the boat will only go into the water one more time this year and that will be to test my ability to overhaul the drive system that I have already began then I will begin the dis-assembly for complete restoration of the boat. I will do all of the work myself the re-builds.

Again, thanks WaterLuvr, Sportster & Grinditout! I appreciate the advice.

 

[gravitydrno]

I definitely want the job done right but I am willing to give it a shot myself first.

 

[gravitydrno]

So armed with my new set of feeler gauges I was able to determine that there is .015 clearance on all but one area of one blade where I was able to get a .017 gauge into so as I had "assumed" (yes I know the meaning!) the clearance was as good as it looked. I must say that after your comments WaterLuvr I did some research and have surmised I just spent a bunch on money I really am not happy that I did. Knowing what I know now I would have gone with a used OEM pump rather than a new replacement as it did not state that it was plastic. I have a friend on the west coast who is sending me two newly re-built OEM pumps for what I paid for cheap plastic. Live and learn....to do more research.

Spoke at length with him about rebuilds and he agrees with you Sportster that I should use a reputable rebuilder and being only three hours away I may use SES to rebuild my cores and not just exchange of course I am still a few months away so I will be doing more investigating before I make a move.

Thanks again guys I appreciate the advice!

 

[gravitydrno]

OK numerous attempts to attach a picture and I think I have it figured out.

Here is the vein on the pump in question....questions was is this pump trash or can something like this be filled in? Worth the effort of just locate good used pumps?

 

[pwgsx]

It doesn't look like a crack, more like from when it was cast or is it the full length of the pump? From the pic it looks like just in the center. If it were mine I would fill with some marine tex and call it a day.

 

[Sportster-2001-951C-Stock]

OK numerous attempts to attach a picture and I think I have it figured out.

Here is the vein on the pump in question....questions was is this pump trash or can something like this be filled in? Worth the effort of just locate good used pumps?
View attachment 26602

That pump looks just fine to me, what you see there is having no impact on performance in any way. If it's something you must do something about then you can cover that up with some JB weld or marinetex epoxy or something but if it were mine I wouldn't worry about anything back there but wear ring clearance and impeller stator bearings. If the clearance is decent (I think 0.020" clearance is acceptable spec, right?) then they're good IMO.

I dunno what the original problem was anymore, maybe I never did really, but if your motor revs and you go nowhere it could be air ventilating your impeller by being sucked out of the bilge through the hull fitting or some air leaks around the pump mount. OR,,,

The other thing that can happen is the PTO splines can strip, when that happens the impeller RPM isn't engine RPM and that's a no-go as well. Oh wait, you said your splines look worn, I bet that's a problem if you can actually see it!

As far as motors go, I'm not sure why you're looking for new ones quite yet if the compression is good (150psi is great!), might check the outer crank seals for air leaks and to do that you'll need to cut out some plywood and innertubes or buy the leak kit.

BTW, don't pressurize your crankcase beyond a few PSI or you risk blowing the seals out of it, follow the service manual pressure recommendation, I'm sure they tell you the correct test pressure.

 

[Sportster-2001-951C-Stock]

What I mean is, if the impeller bearings are toast then the wear ring gets lunched, so if wear ring is good then bearings are probably good too.

 

[gravitydrno]

Sportster....the original problem was "suspected cavitation" as in motor rpm's seem to match what the tach was showing but almost no propulsion from the port side. Upon dis-assembly I found:
1. worn and dried o-rings in stainless carrier ring
2. carbon ring- round and flat surfaces
3. rubber boots very "loose"- no stiffness & no fitted correctly (tension)
4. drive shaft very rusted and worn looking splines
5. small crack in the pump housing veins
6. play in impeller shaft - front to back- bearings spin VERY freely (compared to new pump) have yet to inspect to see if play is bearings
7. wear ring visually good- no chunks
8. impeller visually good on all edges- clearance is .015

I have pics I will upload. From all I have seen in the boat and what I have read it seems I was getting lots of cavitation from drive shaft thru hull at rubber boot. I have bought all brand new from SBT
1. Drive Shaft
2. Pump Housing w/ wear ring
3. Drive Shaft rebuild kit
4. Neoprene seal
5. Impeller removal tool

I had decided to get JB Weld or similar and see what I could do to fill in and fix the pump, get new bearing and keep as a spare (or keep the cheap POS plastic one as a spare!)

 

[gravitydrno]

I have motors in mind because when they sit cylinders fill with oil, I was told that it was the main seals. Know that I have decided to do a full restore on this boat I will learn how to test and move on from there. Don't where in VA you are but we do get quite a few very cold days during winter so I am planning on clearing out room in the shop and doing a complete off the trailer restore for next summer.